What is the meaning of “T” (“X”, “C”) for certain species in the Equilib Results Window?
The “T” indicates the data for that species were extrapolated out of the reported Cp range T(min) – T(max). Cp ranges are given in the List Window (or if you point to a calculated species in the Equilib Results Window and double-click, Compound will list its data). • If T < T(min), the Cp expression is extrapolated. • If T > T(max), the Cp value at T(max) is kept constant above T(max) (except for solutions taken from SGSL and SGTE databases in order to be consistent with other software vendors). If the species is a stable product and has been extrapolated several hundred degrees above its reported Cp range then one may wish to question the validity of the calculation. In this event the Compound program may be used to enter your own data.
The “T” indicates the data for that species were extrapolated out of the reported Cp range T(min) – T(max). Cp ranges are given in the List Window (or if you point to a calculated species in the Equilib Results Window and double-click, Compound will list its data). • If T < T(min), the Cp expression is extrapolated. • If T > T(max), the Cp value at T(max) is kept constant above T(max). If the species is a stable product and has been extrapolated several hundred degrees above its reported Cp range then one may wish to question the validity of the calculation. In this event the Compound program may be used to enter your own data. The “X” refers to allotropes and in most cases it is not important. Where data are missing, we do not permit allotropes to extrapolate into each others Cp ranges. This is because many allotropes tend to extrapolate poorly which is quite significant since the Gibbs energy between allotropes (the basis for selecting that which is most stable) may be quite small. T
